Crushing devices are known in the art for use to reduce large pieces of frangible material, such as but not limited to concrete, rock, asphalt, etc., to smaller pieces. For the most part, jaw crushers now in use have proven to be satisfactory for most of their intended purposes including, feed size, hard rock capability, reduction ratio, product characteristics, throughput, and economy. However improvements in each of these areas are still possible. For example, prior art jaw-type crushers had a fixed jaw and a large heavy movable jaw. One improvement in the prior art provided for jaw-type crushers having eccentrically mounted rotatable rollers driven by motors where the frangible material would pass over at least one of the rollers. Since the frangible material was placed on at least one of the eccentrically mounted rotatable rollers, the motor driving the roller would have to produce sufficient force to allow the roller to produce its eccentric movement, even with the additional weight from the frangible material. Because of the added weight upon such rollers, this type of prior art jaw-type crusher could typically experience more wear and tear than crushers that didn't apply additional weight to an eccentrically mounted rotatable roller.
Therefore entities wishing to break frangible material into smaller pieces would benefit, by needing fewer replacement parts and less repair time associated with installing replacement parts or fixing a roller jaw crusher system, from having a roller jaw crusher system and method which provides for eccentric movement by an element within the crusher where the element is not weighted down with additional weight due to the frangible material passing over such the element. The same entities will realize additional benefits from a roller jaw crusher system that uses at least one of the eccentrically mounted rotatable rollers of the roller jaw crush system to crush the frangible material a first time and a second time, thus resulting in smaller pieces of the frangible material.